Energy efficiency of buildings is a pressing issue that now affects us all. There is increasingly widespread appreciation of the need for better building insulation to combat thermal energy wastage and its associated costs to the environment as well as the direct cost to the property owner or tenant. Alongside cavity wall insulation, loft insulation is the major target for improvement in many homes and a key feature or recommendation point in the now statutory energy efficiency survey that accompanies all residential property transactions in the UK.
UK government and building industry recommendations are for a 270-300 mm depth of insulation material to be laid in the loft/attic between the joists of the loft/attic floor to reduce loss of inexorably rising internal heat into the loft space and out through the roof. Indeed, Part L of the current UK Building Regulations requires a depth of at least 250 mm. Since most joists (also known as ceiling ties) are 84 mm or 100 mm deep, in general the insulation will need to rise 200 mm or more above the top of the joists and thus any flooring subsequently laid over the joists will generally compact the insulation back down by that difference in depth. Such compaction greatly reduces the effectiveness of the insulation, which relies on being un-compacted in order to trap air in pockets and thus should be avoided.
In the case of installing permanent loft flooring in the manner of a loft conversion, turning the loft into proper living space, the issue is normally avoided/addressed by transferring the insulation capability from the floor to the rafters of the roof instead. However, for the more temporary loft flooring that is often installed by home-owners themselves to serve as a platform for storage of belongings in the loft there will generally not be an obligation or desire to expensively line the roof in place of the loft floor.
The compaction of the loft floor insulation is generally ignored until flagged up in a subsequent energy efficiency survey carried out prior to sale of the property. However, this is of course, very energy wasteful and the problem has inspired some consideration in the industry. A primary proposal for addressing the problem is to lay an array of mutually parallel boards/battens edge-on on top of the joists running orthogonal to the joists and to be nailed down to the joists to provide a raised floor with the insulation filled firstly between the joists and then between the battens. This system is time-consuming to install and, if needed, also time-consuming to uninstall and the upper part of the insulation either needs to be laid separately or be locally crushed where the battens run.
A further proposal to address the compaction problem is outlined in GB 2438620A (Milner) and entails provision of box beam spacers that are again laid on top of the joists running orthogonal to the joists and to be nailed down with blocks to the joists. With this latter system the box beam spacers are specially constructed having a rectangular box form with opposing sidewalls and top and bottom walls and to achieve the required insulation depth using the system the insulation material must be inserted into the rectangular box form. This system lacks versatility and although it is somewhat less time-consuming to install than the other prior systems it is rendered awkward by the need to fill the insulation firstly between the joists and then into the spacers and between the spacers rather than simply laying it between the joists.
It is a general object of the present invention to provide a new system and method for laying a loft floor to address the problem of insulation compaction and which is comparatively straightforward and efficient to install and, where needed, uninstall.